Bowling ball dynamics revealed by miniature wireless MEMS inertial measurement unit

This paper presents a novel sensor technology to deduce the dynamics of a bowling ball. The sensor, a miniature wireless inertial measurement unit (IMU), incorporates MEMS accelerometers and angular rate gyros, a microcontroller, a low power RF transceiver, and a rechargeable battery. When embedded in a bowling ball, the IMU transmits the acceleration and angular velocity data that define the dynamics of the ball starting with the bowler’s delivery and its motion in the lane. Example results from professional bowlers illustrate how this technology can be used to assess bowler skill and ball performance. For instance, the IMU accurately measures the spin dynamics of the ball which are crucial to develop the ball “hook.” An analysis of ball dynamics in the lane is distilled to a measurable “hook potential” metric for further assessing bowler skill. Finally, the sensor presented herein is believed to be the world’s smallest, wireless IMU. This highly miniaturized and wireless design will enable parallel training systems for many sports, including basketball, baseball, crew, cricket, golf, fly fishing, soccer, softball, tennis, rowing, among others.     

面向个性化推荐的快速关联规则挖掘算法

关联规则挖掘是解决电子商务推荐问题的重要方法之一.针对传统关联规则挖掘算法在解决移动电子商务环境个性化推荐问题时反复扫描数据库,频繁项挖掘效率低,关联规则挖掘准确率低以及规则大量冗余等不足,提出一个基于事务矩阵和用户兴趣度的关联规则挖掘算法(Matrix-and-Interestingness-based Association Rules Mining,MIbARM).该算法仅需扫描一次数据库,并在挖掘过程中不断缩小算法搜索空间以避免生成冗余候选项,同时避免了冗余规则挖掘,从而提高了挖掘效率.最后,在四组人工数据和160种参数组合的数值实验环境下,引入Apriori、CBAR 及BitTableFI算法对MIbARM进行对比验证.结果表明,在不减少有趣规则的前提下,MIbARM不但可有效避免冗余候选项集的产生,而且大幅减少了冗余规则数量,极大提高了算法的搜索效率,同时提升了个性化推荐的质量,更适用于移动电子商务环境下的个性化推荐问题.     

Myeloperoxidase in Chronic Kidney Disease

Numerous lines of evidence implicate a role of myeloperoxidase (MPO) in the pathogenesis of cardiovascular disease (CVD). It is a well accepted fact that patients with chronic kidney disease (CKD) are at an increased risk for CVD. MPO is a pro-oxidant enzyme which could be involved in the increased susceptibility of these patients to CVD. Hence, the levels of plasma MPO was determined in healthy controls as well as in patients with CKD [stratified with the level of their kidney failure as CKD stages II–V (end stage renal disease)]. Plasma MPO was assayed by a spectrophotometric method. Serum urea and creatinine were estimated on a clinical chemistry analyzer using standard laboratory procedures. The mean plasma MPO levels were significantly lower with advancing stages of renal failure (P < 0.001). There was a positive correlation between MPO and GFR (r = +0.89, P < 0.001) and a negative correlation with urea (r = −0.85, P < 0.001) and creatinine (r = −0.82, P < 0.001). While an inverse association was observed between plasma MPO and urea in CKD patients, such an association was not observed in control subjects (P = 0.43). In conclusion, the decline in plasma MPO levels may be due to the inhibitory effect of uraemic toxins on the enzyme.     

The Jatropha biofuels sector in Tanzania 2005-2009: Evolution towards sustainability?

Biofuel production has recently attracted much attention. Some anticipate substantial social and environmental benefits, while at the same time expecting sound profitability for investors. Others are doubtful, envisaging large trade-offs between the pursuit of social, environmental and economic objectives, particularly in poor countries in the tropics. The paper explores these issues in Tanzania, which has been an African forerunner in the cultivation of a bio-oil shrub called Jatropha curcas L. We trace how isolated Jatropha biofuel experiments developed since early 2005 towards a sectoral production and innovation system, and we investigate to what extent that system has been capable of developing and maintaining sustainable practices and producing sustainable outcomes. The application of evolutionary innovation theory allows us to view the developments in the sector as a result of evolutionary variation and selection on the one hand, and revolutionary contestation between different coalitions of stakeholders on the other. Both these processes constitute significant engines of change. While variation and selection are driven predominantly by localised technical and agronomic learning, the conflict-driven dynamics are highly globalised and occur primarily as a result of reflexive learning about problematic sustainability impacts. The sector is found to have moved some way towards a full sectoral innovation and production system, but it is impossible to predict whether a viable sector with a strong “triple bottom line” orientation will ultimate emerge, since many issues surrounding the social, environmental and financial sustainability still remain unresolved, especially relating to local and global governance.     

“Follow the Water”: Steve Squyres and the Mars Exploration Rovers

Steve Squyres was responsible for assembling the team of scientists, engineers and instruments that formed the Mars Exploration Rovers (MER). Squyres developed a vision that small-scale observations made by a robotic geologist on Mars would be the key for resolving the mystery of water on Mars. Prior to the MER missions, planetary scientists were divided between groups holding that ancient fluvial-like surface features on Mars were formed by water and those holding that the erosive and depositional forces were tied to liquid and gaseous CO₂. At issue was a fundamental understanding not only of early Martian geological processes and early solar luminosity, but also the possibility of life on Mars. To resolve these questions, Squyres and his team developed a new breed of rovers that were capable of identifying minerals and collecting textural observations. The resulting twin rovers, Opportunity and Spirit, have successfully resolved the single most important question about Mars that scientists have been debating for the past 30 years, providing compelling evidence for the action of water on the Martian surface. Squyres and the MER team have also initiated a new era in planetary exploration and inspired a new generation of students to become scientists and explorers. Steve Squyres and the MER team produced fundamental insights into the geology and climatology of Mars. These have resulted in major advances in our understanding of the potential for life on other planets and of life’s evolution on Earth. For the discovery and elucidation of water on Mars through the “robotic geologists” of the Mars Exploration Rovers, Steve Squyres was awarded the 2007 Benjamin Franklin Medal in Earth and Environmental Science.     

Demand articulation in emerging technologies: Intermediary user organisations as co-producers?

User involvement is assumed to be beneficial to innovation processes. Intermediary user organisations contribute to articulating societal demands for innovations. However, the learning processes inside these organisations are still not understood well. Therefore, this paper empirically investigates intermediaries using an event history approach. It yields characteristic learning mechanisms, e.g. concerning the management of expectations or actively building a case. If intermediaries overcome challenges regarding positioning, representation and the level of proactivity, they can play a precarious role in demand articulation in the context of new technologies.     

Murdered bread, living bread: Doris Grant and the homemade, wholemeal loaf

Doris Grant (1905-2003), a middle-class, British housewife, published numerous books from the 1940s into the 1970s urging her fellow housewives to bake organic, wholemeal bread for their families. This article argues that Grant's arguments defy easy categorization as either 'conservative' or 'progressive'. On the one hand, her targeted appeal to women reflected a traditional, conservative understanding of gender roles: women were, first and foremost, wives and mothers and therefore naturally responsible for family diet and health. On the other hand, Grant also pushed her readers to look beyond their homes and recognize a dangerous food supply system that was impinging on their daily lives. She demanded that her readers reject comfortable complicity in this system and preached the value of individual action in effecting substantive change.     

Polymer Materials

Since the second half of the 20th century, polymer materials have already become an essential part of our daily life. The use of polymeric materials has already exceeded that of metals and ceramics in terms of volume and is intimately connected     

A parallel microfluidic channel fixture fabricated using laser ablated plastic laminates for electrochemical and chemiluminescent biodetection of DNA

Herein is described the fabrication and use of a plastic multilayer 3-channel microfluidic fixture. Multilayer devices were produced by laser machining of plastic polymethylmethacrylate and polyethyleneterapthalate laminates by ablation. The fixture consisted of an array of nine individually addressable gold or gold/ITO working electrodes, and a resistive platinum heating element. Laser machining of both the fluidic pathways in the plastic laminates, and the stencil masks used for thermal evaporation to form electrode regions on the plastic laminates, enabled rapid and inexpensive implementation of design changes. Electrochemiluminescence reactions in the fixture were achieved and monitored through ITO electrodes. Electroaddressable aryl diazonium chemistry was employed to selectively pattern gold electrodes for electrochemical multianalyte DNA detection from double stranded DNA (dsDNA) samples. Electrochemical detection of dsDNA was achieved by melting of dsDNA molecules in solution with the integrated heater, allowing detection of DNA sequences specific to breast and colorectal cancers with a non-specific binding control. Following detection, the array surface could be renewed via high temperature (95 °C) stripping using the integrated heating element. This versatile and simple method for prototyping devices shows potential for further development of highly integrated, multi-functional bioanalytical devices.